Warming articles, such as warming blankets and warming mattress pads typically include a user control, such as a dial, that permits a user to set the relative amount of heat output of the blanket. As an example, a user control for a warming article may include settings 1 to 10, with 10 being the warmest setting, and 1 being the least warm. These settings are a relative temperature scale and a setting of 7 on one warming article may not be the same temperature as a setting of 7 on another similar article. This relative temperature measurement requires only gross determination of the temperature of the warming article. Sometimes temperature determination is also used to set an upper safe limit. In both cases, precise calibration of temperature is not required.
Furthermore, an arbitrary numbering system does not provide an intuitive idea of how warm the article will get. A user may know they are comfortable at 72 degrees Fahrenheit. It is preferable, therefore, to have a warming article in which the heating may be set using a known temperature scale rather than an arbitrary numbering scale. However, this requires a control system that has precise knowledge of the temperature of the warming article.
There is thus a need for a warming article with sensor feedback that is precisely correlated to the actual temperature such that each standardized controller will work with any sensor and warming article.